1. Field of the Invention
This invention pertains to electronic ballast systems for gas discharge tubes. In particular, this invention relates to an electronic ballast system for fluorescent light sources which provides a high efficiency in transforming electrical energy into the visible bandwidth of the electromagnetic spectrum. More in particular, this invention directs itself to a transistorized electronic ballast system for fluorescent light sources. More particularly, this invention pertains to an improved transistorized electronic ballast system for dual mode operation of fluorescent light sources. Additionally, the subject invention relates to a transistorized electronic ballast system which provides for a minimal number of electrical components to provide low heat dissipation within a confined volume. Still further, this invention relates to an improved transistorized electronic ballast system which allows for low cost operation and minimizes the manufacturing expenses and labor costs associated with the application thereof. Still further, this invention provides for an electronic ballast system using a DC-AC inverter system which prevents surges applied to the operating transistors through the use of a plurality of inverter transformers which are discrete in nature and thus, there is a minimization of magnetic coupling. Further, this invention directs itself to an electronic circuit wherein if one of the fluorescent light sources is removed from the circuit, there is no additional dissipation of energy.
2. Prior Art
Ballast systems for gas discharge tubes and fluorescent lightbulbs in particular are known in the art. Additionally, ballast systems for a plurality of fluorescent lightbulbs are also known in the art. However, in many prior art ballast systems, the number of electrical components contained within the circuit has been found to be relatively large. Such large number of components has led to such prior art ballast systems having relatively large volumes. The large volumes has been due in part to a number of electronic components in combination with the components used for dissipation of heat due to the disadvantageous thermal effects resulting from high heat dissipation factors when large numbers of components are being used.